The 50% number was made up anyway, it's likely higher than that. GPS especially is pretty accurate, and these tracking systems probably use it when available.
For a single stolen phone, probably not. Though you can still go to their house and then call the phone right as they answer the door. If you hear ringing then that's probable cause.
Either a location is enough for the police to search your place or it is not. Don't pull the kidnapped big eyed little girl card, please.
If crime1 w/ probable cause means you enter the building and crime2 w/ probable cause means you enter the building then there's no reason to bring up tiny girls or puppies.
But obviously there is a difference between trivial crimes and kidnappings. Inconveniencing a few people to save a life is acceptable. The expected utility is positive. It likely is not for more trivial crimes.
As I discussed in my other post, I'd say that:
10% of the time, no location at all
60% of the time, highly accurate location
30% of the time, accurate to a general area, a few hundred feet up to a few miles
2% of the time, totally haywire. Location jumps around randomly, or stays wrong for an extended period of time.
(Statistics are my SWAG, and don't total to 100%).